The present invention generally pertains to injection molding of thin-walled plastic products and is particularly directed to enhancing the strength of thin-walled plastic products.
A prior art mold for molding thin-walled plastic products having a thin-walled area includes a first mold part and a second mold part defining a mold cavity therebetween, encompassed by a parting line, for forming the plastic product, and further defining a gate for admitting injected molten plastic into the cavity. The mold parts define a thin cavity region for defining the thin-walled area of the plastic product; and first and second flow channels which define boundaries of the thin cavity region, and which are portions of the mold cavity that are thicker than the thin cavity region, for directing the injected molten plastic from the gate into the thin cavity region, whereby the molten plastic directed from the first flow channel joins with the molten plastic directed from the second flow channel. A "flow channel" is defined as a portion of the mold cavity which directs the flow of molten plastic. Thin-walled plastic products made with such molds are structurally weak, especially in the regions where the molten palstic directed from the first flow channel joins with the molten plastic directed from the second flow channel.